Cytotoxic hammerhead ribozymes

Small catalytic RNA molecules of the hammerhead ribozyme type were found to have cytotoxic effects unrelated to their intended activity. An expression library of ribozyme sequence variants was constructed in a recA-deficient strain of Escherichia coli such that individual library members differed in regions designed to form base pairs with human immunodeficiency virus-1 (HIV-1) tat mRNA. The parental ribozyme and many variants exhibited a bacteriostatic effect. One variant studied in detail was also bactericidal. When its expression was induced, ribozyme-dependent inhibition of bacterial growth was not observed in recA+ or recA+ lexA3 (Ind-) cells, suggesting that the recombination function of the RecA protein, not the absence of the SOS response, is sufficient to alleviate the cytotoxic effect. These data document the need for careful testing for toxic effects during intracellular studies of ribozyme action.

Treatment of giant cell tumor of bone: a comparison of local curettage and wide resection

BACKGROUND

Giant cell tumor of bone is benign but locally aggressive neoplasm with a tendency for local recurrence. Although various treatment options have been utilized and reported, it remains a difficult therapeutic problem for the orthopedic surgeon.

METHODS

We reviewed the results of the treatment of giant cell tumor of bone in 27 patients. Eleven patients were treated with extended curettage and burring then packing with cement, while 16 patients had wide resection and reconstruction.

RESULTS

At an average of 50 months after surgery, the recurrence rate of curettage was 27% and that of wide resection was 6.25%. Two of the three patients who had a recurrence after curettage were treated by a secondary curettage procedure and were later free of disease. Overall, the local control rate after second curettage and packing with cement was 90.9%. There was no infection in the curettage group but infection occurred in 3 patients of the resection group. Eight patients in the curettage group (80%) had an excellent functional result but only 2 patients in the resection group (13%) achieved an excellent result.

CONCLUSION

This study demonstrates that either curettage and packing with cement or wide resection are effective in treatment of giant cell tumor of bone. There is, however, a better functional result after curettage and packing with cement than following wide resection. We recommend curettage and cement packing for giant cell tumor of bone whenever it is technically feasible.

Morphometric description of the wandering behavior in Drosophila larvae: aberrant locomotion in Na+ and K+ channel mutants revealed by computer-assisted motion analysis

Wandering is a simple behavior in Drosophila larvae prior to metamorphosis. Using the Dynamic Image Analysis System (DIAS) initially developed for analyzing amoeboic movements of single cells, we have analyzed videotaped behaviors of Drosophila larvae at the wandering stage. Previous studies show that mutations in the Na+ channel gene paralytic (para) cause paralysis at 29 degrees C, and mutations in the K+ channel beta subunit gene Hyperkinetic (Hk) lead to leg-shaking under ether anesthesia. The application of DIAS revealed quantifiable abnormalities in the larval locomotion of both ion channel mutants even under "permissive" conditions. Analysis of centroid movement indicates that, compared to wild type, both Hk and para larvae crawled at a slower average speed, but a similar peak instantaneous speed during a contraction cycle. Nevertheless, contraction in the body length was greater in mutants, implying a lower efficiency in conversion of muscular contraction to distance translocation. In addition, each mutant produced a characteristic crawling pattern distinct from the wild-type control. The larval crawling pattern was determined by periods of linear locomotion interposed by non-locomotive, "searching and decision-making" episodes, after which the crawling was resumed in a new direction. Our results demonstrate that mutations in single ion channel subunits resulted in stereotypic modifications in locomotion control and crawling patterns, and that DIAS is a powerful tool in revealing subtle differences in animal behavior and quantifying mutational effects on the interplay of discrete behavioral components.

Identification of rapid turnover transcripts overexpressed in thyroid tumors and thyroid cancer cell lines: use of a targeted differential RNA display method to select for mRNA subsets

The mRNAs of transiently expressed proteins such as cytokines and proto-oncogenes are commonly subject to rapid transcriptional activation and degradation. Transcript turnover is determined in part by association of certain proteins with consensus AU-rich motifs (AUUUA) in the 3'-untranslated region of the transcripts. Here we report a modification of differential RNA display (DRD) to detect differentially expressed rapid turnover mRNAs containing AU-rich motifs from thyroid cancer tissues and cell lines. RNA of normal and thyroid cancer tissues was differentially displayed using a 3'anchor primer to the poly(A) tail and an arbitrary 5'primer incorporating an AUUUA sequence. The appropriateness of the strategy was established by its ability to display known early response genes, such as c- fos, using partially degenerate primers. To test whether the novel cDNAs isolated coded for transcripts subject to rapid turnover, they were used as probes for Northern blots of RNA from clonal human thyroid carcinoma cell lines treated for varying periods with either cycloheximide or actinomycin D. A number of novel differentially expressed cDNA fragments were isolated from human papillary thyroid carcinoma tissues, among them a cDNA with zinc finger motifs and homology to other zinc finger proteins. Using this fragment to probe a cDNA library, a full-length cDNA (ZnF20) was isolated that was 4333 bp in length and contained an open reading frame of 1029 amino acids. The ZnF20 cDNA hybridized to multiple transcripts in a thyroid cancer cell line (8.0, 4.5 and 2 kb) that increased after cycloheximide treatment and decayed <2 h after addition of actinomycin D. The ZnF20 mRNA was overexpressed in three of six thyroid papillary carcinomas as compared with paired normal thyroid tissue controls. The data presented here support the use of a targeted DRD approach for the isolation of rapid turnover mRNAs, many of which may be interesting candidate oncogenes.

Uncemented total arthroplasty in old quiescent infection of the hip

We reviewed the outcomes of 24 cases (24 patients) of uncemented total hip arthroplasty done to treat secondary osteoarthritis due to quiescent previous infection. There were 16 men and eight women aged from 24 to 78 years (mean, 50 yr). Eight patients had proven or probable tuberculous infection and the other 16 patients had a past history of septic hip. The patients were followed for between 2.5 and 7 years (mean, 4.5 yr). According to the Harris hip rating system, 18 of the patients had excellent or good results. Three patients had a preoperative erythrocyte sedimentation rate of 40 mm/h or higher and had a positive bacterial culture. Two of these patients developed reinfection. The other 21 patients had a preoperative erythrocyte sedimentation rate less than 40 mm/h and no reinfection postoperatively. There were five complications other than infection: dislocation with ipsilateral femoral shaft fracture, intraoperative femoral fracture, cup loosening, periprosthetic osteolysis, and nonunion of the greater trochanter. Uncemented total arthroplasty for old quiescent infection of the hip should be considered if the preoperative erythrocyte sedimentation rate is normal and a course of prophylactic antituberculous therapy is given in patients with an old tuberculous hip.

Regulation of thyroid hormones in the secretion of insulin and gastric inhibitory polypeptide in male rats

The effect of thyroid hormones on glucose-induced secretion of gastric inhibitory polypeptide (GIP) and insulin was studied. Male rats were thyroidectomized (Tx) or sham Tx. Sham Tx rats were injected with either propylthiouracil ([PTU] 20 mg/kg intraperitoneally) or saline for 2 weeks. In addition, thyroid-intact rats were injected intravenously with triiodothyronine ([T3]5 microg/kg) or saline 10 minutes before an oral glucose load (3.2 g/kg). Blood samples were collected from each animal via a jugular catheter at 0, 10, 20, 30,45, 60, and 90 minutes following glucose ingestion. Plasma levels of GIP and insulin were measured by specific radioimmunoassays (RIAs). Thyroidectomy-induced hypothyroidism increased the basal level of plasma GIP, but decreased that of insulin. Insulin levels at 10, 20, and 30 minutes following oral glucose were lower in hypothyroid rats than in euthyroid rats. Conversely, GIP levels at 60 and 90 minutes following glucose ingestion in PTU-induced hypothyroid rats were higher than those in euthyroid rats. Furthermore, glucose-stimulated insulin secretion was unaltered by pretreatment with T3, whereas the glucose-induced increase in plasma GIP was completely abolished by preinjection of T3 in thyroid-intact rats. These results suggest that thyroid functions are involved in the regulation of insulin and GIP secretion in rats.

Reimplantation of infected hip arthroplasties using bone allografts

Twenty-two patients with deep infection of an hip prosthesis received delayed reimplantation using bone allografts. Sixteen were done using noncemented components and 6 using femoral components that were fixed with antibiotic impregnated cement. Bulk allografts were used at the acetabular site in 2 patients and at the femoral site in 4 patients. Morselized allografts were used at the acetabular site in 20 patients and at the femoral site in 10 patients. The causative organisms were virulent in 10 hips and low virulent in 12 hips. At an average followup of 4 years (range, 2-7 years), 91% of patients were free of infection and 73% had a successful functional result. Two had a recurrent infection; 1 of them had a pseudomonas infection and another had a methicillin resistant Staphylococcal infection. The recurrence of infection tended to be higher if the causative organism was virulent. The use of bone allografts at the staged reimplantation of the infected hip arthroplasty did not increase the incidence of recurrent infection. Both cemented and noncemented reimplantations had a successful result in eradicating the infection. However, hybrid reimplantation with a cemented femoral component and fixed porous acetabular component had a better functional outcome than noncemented reimplantation using porous femoral component and nonfixed acetabular component.

[Operation directions by comparing financial ratio of 22 provincial hospitals]

Even more restrictive regulations and reimbursement limits seem to be a very heavy burden and stress for most provincial hospitals, especially after the National Health Insurance System has been introduced. The purpose of this project to find a better, universal direction for these hospitals through three steps: 1) Using different financial and accounting ratio indexes to evaluate the general business performance of each hospital. 2) Taking a comprehensive questionnaire with senior managers of each hospital to know their concepts and attitudes concerning external environment and internal operation. 3) Comparing data's correlation and differentiation to ascertain better trends for future operation for all hospitals. The database for this project comes from two resources: 1) Government finance and budget reports of 22 provincial hospitals for the 1994 accounting calendar year. 2) The results of questionnaires returned by 274 senior managers of hospitals, and analysis of these by chi-square test. Through statistical comparison, a number of conclusions can be made: 1) Most hospitals have better operation efficiency if any professional hospital administrator is working for them. 2) The hospital with more comprehensive personnel system shows better business performance. 3) The hospital with routine and formal financial analysis reports always has better business performance. 4) The hospital with poor operational efficiency tends to get rid of restriction or limitation from government's system. 5) The hospital with good operational efficiency has more confidence and desire to improve and change. 6) The hospital with poor operational efficiency is more dependent on outside support from government. 7) The hospital with better business performance has more concern about the impact of malpractice around the hospital. In short, a hospital with poor business efficiency always has more pessimistic attitude and tends to rely on outside resource support. On the other hand, a hospital with more confidence, flexibility and readiness for internal improvement always demonstrates greater business efficiency.

In vivo functional role of the Drosophila hyperkinetic beta subunit in gating and inactivation of Shaker K+ channels

The physiological roles of the beta, or auxiliary, subunits of voltage-gated ion channels, including Na+, Ca2+, and K+ channels, have not been demonstrated directly in vivo. Drosophila Hyperkinetic (Hk) mutations alter a gene encoding a homolog of the mammalian K+ channel beta subunit, providing a unique opportunity to delineate the in vivo function of auxiliary subunits in K+ channels. We found that the Hk beta subunit modulates a wide range of the Shaker (Sh) K+ current properties, including its amplitude, activation and inactivation, temperature dependence, and drug sensitivity. Characterizations of the existing mutants in identified muscle cells enabled an analysis of potential mechanisms of subunit interactions and their functional consequences. The results are consistent with the idea that via hydrophobic interaction, Hk beta subunits modulate Sh channel conformation in the cytoplasmic pore region. The modulatory effects of the Hk beta subunit appeared to be specific to the Sh alpha subunit because other voltage- and Ca(2+)-activated K+ currents were not affected by Hk mutations. The mutant effects were especially pronounced near the voltage threshold of IA activation, which can disrupt the maintenance of the quiescent state and lead to the striking neuromuscular and behavioral hyperexcitability previously reported.

Identification of a potential physiological substrate for oncogenic Ras-activated protein kinases in activated Xenopus egg extracts: correlation with oncogenic Ras-induced cell cycle arrest

Activated Xenopus egg extracts are capable of undergoing cell-free cell cycling. Using these activated extracts, we previously showed that purified, bacterially expressed oncogenic human RasH protein arrests cell cycle progression. Because oncogenic Ras activates many serine/threonine protein kinases in Xenopus oocytes and egg extracts, it is possible that induction of cell cycle arrest involves the action of oncogenic Ras-activated kinases. Thus, the identification of the physiological substrates for oncogenic Ras-activated kinases is important for elucidating the molecular mechanism underlying oncogenic Ras-induced cell cycle arrest. We used 32P-orthophosphate as a label to identify the potential substrates. Our results demonstrated that the 32P-labeling of both a 32 and a 33 kDa protein were greatly enhanced by oncogenic Ras during the incubation of activated Xenopus egg extracts. The enhanced labeling correlated with the induced cell cycle arrest and was contributed by serine phosphorylation. Moreover, the 33 kDa protein was detected only in the presence of oncogenic Ras and was a serine-hyperphosphorylated form of the 32 kDa protein. Furthermore, new protein synthesis was not required for the enhanced labeling, consistent with the concept that the enhanced serine phosphorylation of the 32 kDa protein is by oncogenic Ras-activated protein kinases. In addition to serine phosphorylation, our results also suggested that an as yet unidentified modification of the 32 kDa protein might also be induced by oncogenic Ras. Our results suggest that the 32 kDa protein is a potential physiological substrate for oncogenic Ras-activated protein kinases.

Pelvic mass caused by polyethylene wear after uncemented total hip arthroplasty

A 50-year-old man developed a pelvic mass following uncemented total hip arthroplasty. The mass communicated with the hip via an acetabular defect after loosening of the acetabular component. Operative and histologic findings revealed a foreign body reaction to polyethylene debris. Revision arthroplasty and excision of the pelvic mass were performed successfully through a single incision. A mass adjacent to a loose prosthesis may present as polyethylene failure following total hip arthroplasty. Revision arthroplasty and excision of the mass after an accurate diagnosis are recommended.

Regulated expression of the ets-1 transcription factor in vascular smooth muscle cells in vivo and in vitro

Ets-1 regulates the transcription of several genes encoding extracellular matrix proteins (ie, osteopontin and tenascin) as well as enzymes involved in degradation and remodeling of the extracellular matrix (ie, stromelysin and urokinase plasminogen activator). In the present study, we investigated the regulation of c-ets-1 in cultured rat vascular smooth muscle cells as well as in the arterial wall after balloon injury in vivo. Serum-starved smooth muscle cells exposed to serum for various time points express a major c-ets-1 mRNA transcript of 5.3 kb and minor bands of 4.0 and 2.5 kb with a peak at 2 hours after stimulation. These effects were concentration dependent. Western blotting revealed an increase in 55- and 40-kD immunoreactive ets-1 proteins in cells treated with serum for 2 hours, and binding to an oligonucleotide containing the ets-1 consensus cis-acting motif was demonstrated by electrophoretic mobility shift assay. Ets-1 mRNA abundance was induced with a peak at 2 hours after stimulation with platelet-derived growth factor-BB and with angiotensin II. There was a distinct increase of ets-1 immunoreactivity in the inner layer of the media 2 hours after balloon catheter injury of rat arteries, which declined after 6 hours and returned to the basal level 1 day after vessel wall damage. Arterial c-ets-1 mRNA content was induced with an identical time course. These findings suggest that c-ets-1 may be of importance in the mitogenic signaling pathway of smooth muscle cells grown in culture. In addition, ets-1 may play a role in the activation of smooth muscle cells in vivo after mechanical injury of the vessel wall. Because the ets-1 transcription factor activates the gene expression of a number of mRNA species involved in matrix deposition and degradation, these data are compatible with a role for ets-1 in vascular remodeling and/or cell migration.

Nucleotide sequence of a 1446 base pair SalI fragment and structure of a novel early gene of Leucania separata nuclear polyhedrosis virus

A 1446 bp SalI fragment of LsNPV was sequenced by the silver staining method, and two large open reading frames (ORFs, ORF1 and ORF2) were found, both contain typical characteristics of the 5' regulatory elements of baculovirus early genes. ORF1 is 345 bp long with the capacity to encode a putative protein of 114 amino acid residues with MW about 13 kDa and was designated p13 gene, ORF2 comprises 248 bp from the 3' end of the fragment. In the untranslated region (UTR) of ORF1, a 33 bp mini cistron (ORF3), a core recognition sequence (CGTCG) for many bHLHzip transcription factors and a late promoter sequence TTAAG are present. In the UTR of ORF2, two host transcription factor binding elements (CACGTG and GATA motif) and two CGT motifs were found. Some regular leucine zipper-like structures, designated leucine trans-conformation structure and LVT repeat, were found near the N-terminus and the middle of p13 protein. The leucine trans-conformation structure that is near the N-terminus consists of 4 leucines and 7 other amino acids between every two leucines, and every leucine is located at a conformation shift point of the predicted secondary structure of the p13 protein. In LVT repeat, L-6aa-V-6aa-T-6aa is repeated once. The functions of those structures remain unclear, and the two ORFs, not found in the genome of Autographa californica nuclear polyhedrosis virus, are possibly two new genes.

Reconstruction of below-knee stump using the salvaged foot fillet flap

Three cases of below-knee stump reconstruction, using cross-legged, free sole flap, free foot filleted flap, and island pedicle sole flap, were reported. The variability of the flap size provided satisfactory coverage as needed in all cases. The causes of amputation were acute trauma and chronic osteomyelitis. The contour of the stump, the sensory recovery, the preserved range of motion of the knee joint, and the long-term durability were satisfactory in these patients. Some pitfalls of this procedure and criteria for evaluating the distal extremity soft tissue with respect to their suitability for use are discussed.

Fucosyltransferase and alpha-L-fucosidase activities and fucose levels in normal and malignant endometrial tissue

Previous immuno- and lectin-histochemical studies using mAbs and Ulex europaeus lectin I, which recognize various fucose-containing blood group antigens, have shown an increased expression of Lewis and H blood group antigens in endometrial carcinoma. We investigated the biochemical basis of aberrant fucose-containing antigen expression by comparing the activity of fucosyltransferases (FTase) and alpha-L-fucosidase in tissue biopsies from normal (n = 18) and malignant (n = 20) endometrium. Alteration of FTase activity in tumor tissue homogenates was evaluated by using a panel of FTase substrates including N-acetyllactosamine (type 2), lacto-N-biose I (type 1), and phenyl-beta-D-galactoside. Based on histological subtyping, the endometrioid group (n = 14) showed a significant (P < 0.05) increase in tumor FTase activity with all three substrates, while no significant increase was detected for the papillary serous group (n = 4). Matched pair analysis of normal and tumor tissue from a subgroup (n = 5) of the patients with increased tumor enzyme activity also showed higher FTase activity (P < 0.05) in the tumor tissue when the type 1 substrate was used. Regression analysis showed a correlation between the FTase activities acting on type 2 or type 1 substrates (r = 0.821 and r = 0.722, respectively) and the endogenous fucose levels in tumor homogenates. Spectrophotometric analysis of alpha-L-fucosidase activity using p-nitrophenyl-alpha-L-fucoside revealed a higher activity in tumor homogenates than in normal homogenates (P < 0.05) and, therefore, could not account for the enhanced expression of fucose-containing antigens. The current study suggests that aberrant expression of fucose-containing antigens, such as the H and the Lewis blood-group antigens, in endometrial carcinoma is consequential to the change in FTase rather than in alpha-L-fucosidase activity. In addition, the investigation suggests that different glycosylation mechanisms are operative in different subtypes of endometrial cancer.

Fabellar impingement after total knee replacement--a case report

An unusual postoperative knee pain caused by fabellar impingement after total knee replacement is described. A 68-year-old woman with knee arthrosis had large fabellae in both knees. She had total knee replacements of both knees. One knee developed fabellar impingement to the knee prosthesis, while the other knee was free of symptoms due to simultaneous fabellectomy during knee replacement. At 3-month postoperative follow-up, pain and local tenderness at posterolateral aspect of the left knee was noted during flexion up to 90 degrees. Physical examination revealed a tender fabella on the posterolateral part of the left knee. The lateral radiograph of the knee revealed a large fabella impinging on the prosthesis. The symptoms and signs were alleviated after surgical excision of the fabella. Careful evaluation of the preoperative lateral radiograph of the knee is necessary to detect a large fabella. If it is present and larger than 1 cm, excision during knee replacement is recommended.

Gastric perforation in the neonate: clinical analysis of 12 cases

Gastric perforation is a rare abdominal catastrophe which associated with high mortality in newborn infants. From June 1978 to July 1991, twelve cases of neonatal gastric perforation presented at Chang Gung Memorial Hospital. Male to female ratio was 9:3. The most common presenting signs were abdominal distension (100%), feeding intolerance (92%), respiratory distress (67%) and poor activity (58%). All cases had significant symptoms between two and five days of age. All of the abdominal plain film showed pneumoperitonium. The most common site of perforation was the great curvature of the stomach (83%). Among the 10 pathological reports available, 8 cases had ischemic change and 2 cases had hemorrhage and inflammatory cell infiltration. There was a high mortality rate of 58% in this series. Male, hyponatremia (serum sodium < 130 meq/l) and metabolic acidosis (pH < 7.3) were poor prognostic factors. This report suggests that early diagnosis and early management before clinical deterioration of the metabolic status may improve prognosis for neonatal gastric perforation patients.

Vitamin B-6 status indices are lower in pregnant than in nonpregnant women but urinary excretion of 4-pyridoxic acid does not differ

The cause of reduced plasma pyridoxal-5'-phosphate (PLP) concentration and the validity of plasma PLP concentration as a vitamin B-6 status indicator during pregnancy are not well understood. In this study, pregnant and nonpregnant women consumed a controlled diet for 5 d to exclude dietary intake as a factor in altered vitamin B-6 metabolic utilization. Plasma PLP and pyridoxal (PL) concentrations were significantly lower and higher, respectively, and plasma PL+PLP concentration was significantly lower during pregnancy. When plasma PLP and PL concentrations were normalized based on plasma albumin concentration, the differences were less marked but were still significant. The erythrocyte aspartate aminotransferase activity coefficient was significantly greater in pregnant women which is a further indication of reduced vitamin B-6 concentrations in the blood. No difference was observed in the urinary excretion of 4-pyridoxic acid between the pregnant and nonpregnant women. Results of this study demonstrate that vitamin B-6 status indices are lower during pregnancy without differences in the urinary excretion of 4-pyridoxic acid.

Intraarterial cisplatinum and intravenous adriamycin for primary hypervascular bone tumor: experience of seven cases

Seven consecutive cases of primary hypervascular bone tumor, encountered between January 1991 and September 1992, were treated with intraarterial cisplatinum and intravenous adriamycin infusion. There were four osteosarcomas, one malignant fibrous histiocytoma, one chondrosarcoma and one case of primitive neuroectodermal tumor. Local symptoms were markedly relieved, or disappeared, in 71% (5/7) of cases after the first course of treatment. Sclerotic changes of bone tumor occurred in 100% (6/6) of cases after two courses of chemotherapy. Progressive decrease of tumor stains was noted in 100% (6/6) of patients during angiographic assessments. On exploration, no gross tumors were found in 80% (4/5) of the cases that received limb-sparing surgery. Although disappearance of symptoms and sclerotic changes of bone tumor predicted a good response to treatment, the degree of decrease of tumor stains corresponded best with the extent of tumor necrosis. Our study verified the effectiveness of intraarterial cisplatinum and intravenous adriamycin infusion in treating primary hypervascular bone sarcomas. Further studies with more cases are necessary to define the optimal duration of postoperative adjuvant chemotherapy.

Allograft transplantation in aggressive or malignant bone tumors

Twenty-three patients with aggressive benign or malignant bone tumors had segmental allograft replacements after resection of the tumors. The mean age of the patients was 30 years of age. The mean length of the allografts was 14 cm. The allografts consisted of intercalary allograft (5), allograft arthrodesis (12), and allograft-prosthetic composite (6). Intramedullary fixation with or without additional compression plate was used to osteosynthesize all the osteotomy sites with the exception of one in which a long nail plate was used. A supplement of autogeneic bone grafts at the allograft-host junction was performed in 18 patients. Seven patients received preoperative and postoperative chemotherapy for high grade sarcomas. At an average follow-up period of four years, 78% of the patients had excellent or good results. The union rate of the grafts was 86%. Supplement with autografts shortened the union time of the allograft from 15 to eight months. One patient had a tumor recurrence and one died of the disease. Other complications included one delayed union, two nonunions of the allograft, two late infections, and one neuropathy. Allograft transplantation is an acceptable method for tumor reconstruction. The adjuvant chemotherapy did not have significant adverse effects on its outcome. Complications that relate to allografting are common, but most of them are salvageable.

Prognostic factors in 43 cases of osteosarcoma

Osteosarcoma is the most common primary bone malignancy. The purpose of this study was to investigate the prognostic factors in the overall and disease-free survival rates by using univariate methods and Cox's multivariate regression model. Patients from Tri-Service General Hospital and Chang Gung Memorial Hospital in Kaohsiung with pathologically proven high-grade osteosarcoma were recruited for this study. There were 29 (67.4%) men and 14 (32.6%) women with a mean age of 17.8 years (range 8 to 35 years). Twenty-five cases (58.1%) were stage IIB, and 18 cases (41.9%) were stage III. The overall five-year survival rate was 15% for these 43 cases. Additionally, the disease-free survival rate was 20% at five years for the 25 stage IIB cases. Univariate and multivariate analyses showed that male gender, stage III disease, surgery only, radiotherapy only, chemotherapy only, no treatment and proximal extremity location were the unfavorable factors associated with death in these 43 cases; while male gender, radiotherapy only, chemotherapy only, no treatment and an elevated serum alkaline phosphatase level were the unfavorable factors associated with recurrence for stage IIB cases.

Multiple schwannomas of the foot: report of a case

Schwannoma, a relatively common tumor of the nerve sheath, rarely involves the foot. A review of the literature disclosed that most reports of schwannoma of the foot were solitary tumors. There has been only one reported case of multiple schwannomas of the foot. We report a case of multiple schwannomas involving both the medial and lateral plantar nerves of the right foot. The patient had been treated for plantar fasciitis for the previous eight years. After excision of one tumor, magnetic resonance imaging (MRI) was used in the diagnosis, revealing four additional tumors. These tumors were also successfully excised and the patient's symptoms relieved. Patients with prolonged intractable pain and tenderness of the foot may require examination by MRI or sonography to search for deep tumors impinging upon the plantar nerves.

A case of massive osteolysis after knee prosthesis polyethylene failure

A case of massive osteolysis of the distal femur in response to particulate polyethylene from a broken uncemented tibial component is described. The osteolysis was so extensive that it made the revision arthroplasty extremely difficult. Early detection and early revision is recommended.